In this paper, an innovative evolutionary computation approach to automatic generation of analog integrated circuit layouts is presented. The proposed design flow starts by a layout template description, which is independent from technology, although including placement and routing constrains. Then, the layout is generated using an evolutionary optimization kernel and following the traditional sequence, first, the placement and, then, the routing. Using the guidelines defined by the designer, placement and routing are adjusted accordingly to the new set of specifications. Moreover, a module generator is also introduced in order to allow the automatic generation of different instances for each of the block composing the layout template and, therefore, automatically enlarging the solution search space. Finally, the first complete implementation of the LAYGEN tool is presented and demonstrated for typical analog integrated circuits structures.